NBC said it will premiere many of its new fall shows three weeks early this year when the Summer Olympics end — the same week as the Republican National Convention. The early start aims to take advantage of the promotional opportunity afforded by the Olympics, which end Aug. 29, with the convention not a consideration, said Jeff Zucker, president of the NBC entertainment, news and cable group.

The convention in New York begins on Aug. 30.

The days of broadcast networks devoting all of their prime-time schedules to convention coverage are long gone. NBC News hasn't announced its coverage plans yet, but it's likely to be similar to 2000, with a one-hour prime-time wrap-up of convention highlights each night. (More lengthy convention coverage will be provided by cable outlets Fox News Channel, CNN, C-SPAN and the NBC-owned MSNBC and CNBC.)

Political parties consider their conventions a kickoff to the fall campaign, and spend considerable time and money crafting their message. A representative of the Bush-Cheney campaign didn't immediately return a call for comment.

Zucker said NBC might pull in more viewers to its convention coverage with original programming leading into it, as opposed to the usual late-summer reruns.

"We're not abdicating our coverage of the convention," said Zucker.

In the TV world, NBC's scheduling change is a bold move, and an indication that the traditional demarcations between a fall season and rerun season are fading.

During its Olympics coverage, NBC will almost certainly bombard viewers with commercials about its new fall shows. That promotional opportunity would be diminished if NBC then waited for three weeks to start the new schedule, Zucker said.

Some networks experimented last fall by premiering a handful of shows early, and drew strong ratings — for The O.C. on Fox and Whoopi on NBC, for example.

"There's no question we're at a time in television where very few of the old rules apply," Zucker said.

There's no indication yet whether NBC will revert to a traditional late-September season opening in the future, or if any of its rivals will change their plans to compete.